Risk behaviors, especially sexual behaviors and IV drugs use, are of much concern in relation to the development and transmission of AIDS. Drug use and high frequency of unsafe sexual activity make the male prostitute populations especially likely to come into contact with the Human Immunodeficiency Virus (HIV). Because of their propensity toward risk-taking behaviors, including substance abuse, unsafe sexual behaviors, and prostitution, male prostitutes likely serve as an important bridge of transfer of HIV to both heterosexual and homosexual populations. The proposed research will examine male prostitutes' lifestyles, unsafe substance abuse and sexual practices, knowledge and attitudes towards AIDS, and psychological symptoms in relationship to HIV seroprevalence. Two hundred forty male street prostitutes from New Orleans will be recruited, constituting a representative stratified sample ranging in age from 12 to 34, including Caucasians and Blacks, and IV and non-IV drug users. Information on lifestyle, sexual and drug risk-taking behaviors, social support, psychological symptoms and self-esteem will be obtained by means of semistructured interviews and questionnaires administered by field researchers. Blood samples will be collected to determine incidence of HIV seropositivity. The study takes a step forward in providing new information that may ultimately help reduce the spread of HIV infection among male prostitutes, thus decreasing its transmission to the larger heterosexual and homosexual populations.